This paper proposes a theoretical method using finite element analysis(FEA) to calculate the plastic collapse loads of pressure vessels under internal pressure,and compares the analytical methods according to three cr...This paper proposes a theoretical method using finite element analysis(FEA) to calculate the plastic collapse loads of pressure vessels under internal pressure,and compares the analytical methods according to three criteria stated in the ASME Boiler Pressure Vessel Code. First,a finite element technique using the arc-length algorithm and the restart analysis is developed to conduct the plastic collapse analysis of vessels,which includes the material and geometry non-linear properties of vessels. Second,as the mechanical properties of vessels are assumed to be elastic-perfectly plastic,the limit load analysis is performed by em-ploying the Newton-Raphson algorithm,while the limit pressure of vessels is obtained by the twice-elastic-slope method and the tangent intersection method respectively to avoid excessive deformation. Finally,the elastic stress analysis under working pressure is conducted and the stress strength of vessels is checked by sorting the stress results. The results are compared with those obtained by experiments and other existing models. This work provides a reference for the selection of the failure criteria and the calculation of the plastic collapse load.展开更多
Electromagnetic self-induction theory and computer are adopted and study of online monitoring technique for wire-core belt is conducted, the study shows that there is direct proportion between distance Ⅰ of broken en...Electromagnetic self-induction theory and computer are adopted and study of online monitoring technique for wire-core belt is conducted, the study shows that there is direct proportion between distance Ⅰ of broken ends and output volt Ⅴ, when Ⅰ ≥60 mm, Ⅴ keeps constantly, the running speed v of wire-core belt has no big effect on output volt Ⅴ, there is inverse proportion between the height h from probe to the surface of the belt and output volt Ⅴ, when h≥30 mm, Ⅴ tends to be zero. Based on the test result, on-line monitoring installation is developed, the practice proved that the accuracy of broken wire monitoring can be above 95%, the monitoring accuracy of joint twitch can be 0 .04 Ⅴ/mm.展开更多
基金Project (Nos. 2006BAK04A02-02 and 2006BAK02B02-08) supported by the National Key Technology R&D Program, China
文摘This paper proposes a theoretical method using finite element analysis(FEA) to calculate the plastic collapse loads of pressure vessels under internal pressure,and compares the analytical methods according to three criteria stated in the ASME Boiler Pressure Vessel Code. First,a finite element technique using the arc-length algorithm and the restart analysis is developed to conduct the plastic collapse analysis of vessels,which includes the material and geometry non-linear properties of vessels. Second,as the mechanical properties of vessels are assumed to be elastic-perfectly plastic,the limit load analysis is performed by em-ploying the Newton-Raphson algorithm,while the limit pressure of vessels is obtained by the twice-elastic-slope method and the tangent intersection method respectively to avoid excessive deformation. Finally,the elastic stress analysis under working pressure is conducted and the stress strength of vessels is checked by sorting the stress results. The results are compared with those obtained by experiments and other existing models. This work provides a reference for the selection of the failure criteria and the calculation of the plastic collapse load.
文摘Electromagnetic self-induction theory and computer are adopted and study of online monitoring technique for wire-core belt is conducted, the study shows that there is direct proportion between distance Ⅰ of broken ends and output volt Ⅴ, when Ⅰ ≥60 mm, Ⅴ keeps constantly, the running speed v of wire-core belt has no big effect on output volt Ⅴ, there is inverse proportion between the height h from probe to the surface of the belt and output volt Ⅴ, when h≥30 mm, Ⅴ tends to be zero. Based on the test result, on-line monitoring installation is developed, the practice proved that the accuracy of broken wire monitoring can be above 95%, the monitoring accuracy of joint twitch can be 0 .04 Ⅴ/mm.
